def fac(k):
    i=2
    t=1
    while i<=k:
        t *=i
        i +=1
    return t
def sum(n):
    s=0
    i=1
    while i <=n:
        s=s+fac(i)
        i+=3
        return 5
print('1!+2!+3!...50!=',sum(50))
    